One of our test drivers averaged 46.9 mpg over 332 miles (mostly highway) with the 2012 Volkswagen Passat TDI.

In the article “It’s Diesel’s Time to Shine,” Consumer Guide Automotive lists 11 advantages (and some drawbacks) to owning a diesel-powered car. The main reason is fuel economy. According to the EPA, the TDI (turbodiesel) versions of the 2012 Volkswagen Passat, Golf, and Jetta SportWagen each get 34 mpg in combined city/highway driving.

Those are good numbers, but VW TDI enthusiasts insist that those estimates are low. And we agree. In real-world driving (with, admittedly, an emphasis on highway driving), we greatly exceeded the EPA estimates with the Passat, Golf, and Jetta SportWagen.

Below are the fuel-economy numbers that we got while driving these cars, as well as comments by the drivers. The Passat numbers are especially impressive considering the car’s size. It has the second-largest wheelbase in the midsize-car class; it’s a big, roomy sedan. The Jetta SportWagen is one of the heaviest vehicles in the compact-car class, and yet we still exceeded 43 mpg with that car. Now if diesel fuel just weren’t so darn expensive. . . .